Joseph jobin



UNITED STATES PATENT OFFIOE.

JOSEPH JOBIN, OF S'l. MAND, NEAR PARIS, FRANCE.

VALVE 0F STEAM-ENGINES.

Specification of Letters Patent No. 21,682, dated October 5, 1858.

To aZZ wlw/ml t may concern:

Be it known that I, JOSEPH JOBIN, of St. Mand, in the Department of theSeine and the French Empire, have invented certain new and usefulImprovements in Steam-Engines; and I hereby declare that the followingis a full, clear, and exact description, reference being had to theaccompanying drawing.

The object of my invention is to avoid pressure produced by theimpelling fluid of the valve in steam and other engines on the valveseat, and thereby diminish the requisite force to move the valve, animportant consideration particularly in locomotive and marine engines.

The system I adopt to carry out the object above named is open tonumerous modifications and applicable with advantage to existing motorsas well as to those yet to be constructed.

The general principle of my invention consists in giving to the valve aprismatic shape, being in its cross-section for instance, of either ofthe forms shown in Figures 1, 2, 3, 4, of the accompanying drawing; andinclosing said valve in a case which serves as a guide to it in itsreciprocating travel. The interior of this valve case is constructedwith recesses arranged opposite the steam ports in the engine cylinderfor the purpose of obviating lateral pressure. The valve is hollow toreceive the steam within it from either or both ends of the chest inorder that the valve shall be exposed to equal pressure on both ends.

In order to illustrate the advantages and peculiarities of this myimprovement I show in the annexed drawing two modifications of it, asapplied to horizontal steam engines.

Fig. 5, represents a vertical longitudinal section through a locomotiveengine cylinder provided with my new improved sliding balance valve (A).Fig. 6 represents a transverse vertical section of the same. Figs. 7 and8 are longitudinal and trans verse views of the valve detached; andFigs. 9 and l0, represent a face and edge view of a movable guide platearranged and adjustable along one side of the chest against which thevalve moves. The latter of these figures shows on one side of the guideplate a movable wedge serving the triple purpose, of adjusting saidplate to meet wear of the valve of tightening said plate to therequisite pressure against the valve, and of obviating the necessity ofremoving the case for adjustment of parts, whereby the great advantageis derived of preserving the original joints.

By reference to the above figures it will be seen that the lower portionof the valve is of the ordinary D form having lips (a a) and exhaustopening (a2) corresponding with or serving to control the steam ports(Z, Z) and exhaust passage (Z2) but wherein this valve differsessentially from others is in its being surmounted by a prismatic cap,which cap is cast in one piece with the lower portion of the valve andprovided with a longitudinal passage through it. rIhe lower portion ofthe valve that forms the base of the prism which in this instance istriangular, plays on the valve seat of the cylinder, while the uppersides of the prism are embraced by two corresponding sides of the chestwhich serve the valve as a guide in its reciprocating travel imparted toit by the valve rod (t). Instead of the valve chest being made of ashape corresponding to the prismatic form of the valve, it may be of theordinary rectangular form fitted with a lid having a prismatic recessedprotuberance entering the chest for the valve to fit and play against.Such construction it will be obvious, admits of my prismatic valve beingapplied to valve chests of engines now in use without requiring anyalteration of the chest or disposition of its apertures.

The steam from the boiler enters the chest (B) either at one end (Z2) oras before mentio-ned, simultaneously at both ends, and traversing thehollow valve presses equally on both extremities of the valve andv thusbalances it in the longitudinal sense or endwise.

The steam contained in the engine cylinder which has produced or isproducing the pistons travel, pressing through the ports (Z or Z), onthe face of the valve, has a tendency to lift the valve and press itagainst the upper portion of the case, but this effect I counteract bythe grooves or recesses (0,0) which admitting steam produces acounteracting pressure thereto. The grooves, although opposite to theports (Z Z) .do not communicate with the said ports.

The escaping steam entering the exhaust opening (052) in the valve, inits passage to the exhaust outlet (Z2), has a tendency also to lift thevalve; this I counteract by allowing steam from the hollow valve, topass y through the side of the valve by apertures (d Z d) and act with adownward force on the valve; these apertures are of area and numbercorresponding to the dimension of the valve. It is necessary even togive an excess of downward pressure, in order to keep the valve firm onthe valve seat. Instead of the apertures (CZ al CZ) the exterior sidesof the valve or interior sides of the valve casing may be grooved.

In varied or long stroke of the valve, it is desirable to avoidaccumulation of dirt in the play of the valve, at its ends androughening or wear of the ends of the valve, by constructing the valvecase and valve seat with recesses (e e) as shown in Fig. 5. By such aconstruction of balance valve, the friction and consequently the wear ofsurfaces in contact is very little, almost none, but evidentlyinfinitely less, than is the case with the ordinary steam valve.

To obviate difficulty and expense of adjustment, in the case of wear, Iapply a mechanical means, consisting of a movable plate (D) shown inFig. 9. Arranged along the side of the prismatic valve and which can betightened to any required degree, by a wedge (E) and screw (Fig. 10)operated by nut on the outside of the case, the tightening of said wedgeserving` to bear the valve down on its seat by reason of the angular orprismatic form of the valve and casing. In this case, the grooves (f f)which admit steam to counteract upward liftof the valve on the one sidewhere the packing plate is arranged, are made in the plate itself,corresponding to the grooves on the other side in the steam chest. Incase of want of room in the casing to insert a valve having a triangularcap, the top of the valve may beV truncated so as to give trapezoidalsection to the valve, as shown in Fig. 4:. The sides of such trapezoidalform of valve, may be more or less inclined, for the purpose of insuringa balancing action, by the means hereinbefore described.

The following figures show another modification of my sliding balancevalve, which consists particularly in the application of a` prismaticalvalve, having a square or rectangular cross section as indicated inFigs. 2 and 3. Fig. 11 represents a longitudinal section through theaxis of the cylinder. Fig. 12, is an end view of the same, having theend plates of the cylinder and valve chest removed. Figs. 13 and 14 aredetails of the lower portion of the steam chest which incloses the valveand serves it as a guide. Figs. 15 and 16, are detail views of the upperpart of said chest.

It is easy to see that this second disposition or arrangement answersthe same purpose as the one previously described, of which this is but amodification.

The steam chest is made in two parts, the

first of which (B) rests and is bolted on the valve seat, while thesecond part (B) is jointed to the former by means of screws or bolts.

The valve A is a hollow tube throughout the who-le of its length andterminates at its extremities in two lips (a a) of square section, andwhich slide upon parts of a similar form in the base of the upper partof the chest.

Two grooves (c c) are provided in the chest to correspond to the steamports (l Z) vof the cylinder (c) and a third larger groove (c2) is alsoprovided corresponding to the exhaust opening Z2) ow, supposing steamenters Vthe chest through the pipe (o) which communicates with thegenerator, it will be readily seen that in order to fill the said chest,the steam has to travel through the interior of the valve before it canpass through the port (Z) to press against the piston (P) and drive itfrom the left to the right; the steam escaping from the opposite side ofthe piston enters the space (C2) and passes therefrom to the escape pipe(E). l

It will be seen that the valve during its movement receives equal andbalancing pressures on its extremities and also on its lateral surfacein as much as the steam is both in and outside. When the valve is movedso that the lips (a af) pass the ports and as they uncover the same, itwill be seen that the steam takes an opposite direction to that which itbefore took, but the effects of pressure on the valve are the same,keeping it in equilibrium in the steam in such a manner, that in orderto move it, there is no other friction to overcome besides that accruingfrom its own weight. To diminish this friction, the parts in contact maybe greased and loss of steam from the chest avoided by use of stufng box(T) for the rod to play through.

This mode of constructing sliding balance valves is applicable to allsteam engines, that is, to locomotives, portable engines, marineengines, as well as to stationary engines whatever be the impellingfluid used.

In Figs. 17 and 18 I show another modification, in which t-he steaminstead of entering at one of the extremities of the chest, is made toenter by two orifices (o o) and to escape at the center of the chest byan outlet (02). In this case the valve (A) shown in Fig. 17, isnot'hollow and terminates at its extremities in two square disks (i i)of the same form and description as the lips (a a) in Fig. 11. By thisarrangement it is not necessary to close the ends of the steam chestconsequently-no stufling box is required.

In Fig. 18. The steam is shown to enter the chest by a single opening(o) the escape taking place at (02). In this instance the form andguided in its reciprocating travel by and Within a steam chest open orclosed 15 at its ends, but surrounding in a close Inanner the sides ofsaid valve substantially as and for the purposes set forth.

In testimony whereof I have signed my name to this specication beforetwo sub- 20 scribng Witnesses.

J. J OBIN.

Witnesses S. RICHARDS, MENGE A. MIENLIN.

